[rsd18]

Dear All

I would like to as if anyone has an suggestions on the best way to solublize the membrane component, phosphatidylinositol (PI) in water. I would like to incorporate it into a protein crystal as a cocrystallised ligand. Any ideas or comments would be greatly appreciated

 

[Yggdrasil]

Since PI is a phospholipid it may be slightly water soluble and you may be able to just add it to your protein and attempt to crystalize it without anything to solublize it.  Alternatively, you could try using some mild detergent to solublize it (e.g. octyl-glucoside or LDAO), but it is generally difficult to crystalize protein in the presence of detergent.  It may also be possible to chemically modify the PI in order to make it more soluble, such as just using the phosphoinositol group or removing the fatty acyl chains (though this depends on what part of the PI molecule your protein recognizes).

Perhaps if you provide more information about the protein you're trying to crystallize we can provide more specific advice.